Structural system

ABSTRACT

A system for the attachment and support of covering or closure members to a structure, particularly where the structural members are formed from precast beams and slabs. A new technique for applying a facia member to the ends of beams forming a roof structure, or applying a spandrel between two columns is disclosed, together with a new technique for applying precast curtain wall panels to a building.

United States Patent Chapman, Jr. 1 Oct. 21, 1975 [5 STRUCTURAL SYSTEM 3,465,996 9/1969 VonWedel H 52/255 x Inventor: Roger p Jr-, 93 Mohawk FOREIGN PATENTS OR APPLICATIONS Drivewamngford, Com 06492 071 9/1921 Sweden .1 52/510 22 Fi d; Feb. 4 1971 1,174,629 11/1958 France 1 52/235 1,199,515 6/1959 France.... 52/236 [21] Appl. N0.: 113,050 1,241,861 8/1960 France 1 1 52/235 928,673 6/1963 United Kingdom 52/235 Data 1,066,525 4/1967 United Kingdom 52/126 [63] Continuation-impart of Ser. No. 793,470, Jan 23,

1969 abandoned Primary Examiner-Alfred C. Perham .4 52 11.5. C1. 52/94; 52/125; 52/235 Agen De and Montgome" [51] Int. Cl. E04B 7/18; E04B 2/88 [58] Field of Search 52/122, 126, 235, 236, A ST ACT 52/510 51 5131 941 A system for the attachment and support of covering 0r closure members to a structure, particularly where [561 References cued the structural members are formed from precast UNIT TAT S PA T beams and slabs. A new technique for applying a facia 2,171,338 8/1939 Henderson 52/220 b r to he ends of beams forming a roof struc- 2.88l,876 4/1959 Williams 52/122 ture, or applying a spandrel between two columns is 3,121,976 2/1964 Ziegenfelder 52/235 X disclosed, together with a new technique for applying Ward, .11 1 1 1 1 X precast curtain wall panels [0 a 3,216,157 11/1965 Pinter 52/126 X 3,378,969 4/1968 Larger 52/235 X 12 Claims, 8 Drawing Figures US. Patent Oct. 21, 1975 Sheet 1 of3 3,913,287

Roqev 5. Chavman, 6v.

HERE-E E- US. Patent Oct.21, 1975 Sheet 2 of3 3,913,287

INVENTOR Roqer 5. Chapman, Jr.

BY D1 M9 W W fim is U.S. Patent Oct. 21, 1975 Sheet 3 of3 3,913,287

INVENTOR R061 5. (Hwoprmauq 3v.

D 4 m9 WWW ATTORNEYS STRUCTURAL SYSTEM This application is a continuation-impart of my copending application Ser. No. 793,470, filed Ian. 23, 1969, now abandoned.

This invention relates to structures, and more particularly relates to structures for applying pre-cast facias, spandrels and wall panels to the framework of buildings for decorative, enclosing and safety purposes.

In many buildings, particularly commercial buildings, the roof thereof is formed by a plurality of parallel precast concrete beams. Such construction commonly requires a facia or trim member running perpendicular to the roof beams for the sake of appearance and sealing against the elements.

Due to the ordinary manufacturing tolerances in precast concrete members there is considerable adjustment and shimming required to have the present facia members established to a good line and grade. With the system now in common use a supported facia is attached to the roof members by use of steel clip angles and plates cast into the concrete. After the facia is properly aligned the plates and angles are welded together fastening the supported facia to the supporting members.

The shimming and aligning process is slow and the alignment is often not completely accurate, and further requires drilling into the end of the supporting members through a hole cast in the facia. This drilling is an expensive process requiring scaffolds and frequently the drill runs into steel reinforcing members in the cast concrete. Even after attachment to the facia member, the drill holes must be patched, but the patches never match the rest of the facia member.

Accordingly, the present invention provides a new and improved technique and construction of joining precast members to a building or frame thereof.

Another object of this invention is to provide a new and improved structure for supporting a vertically disposed member from a building structure.

Another object of this invention is to provide a new and improved structure for supporting a facia member from the ends of roof beams.

A further object of this invention is to provide a new and improved structure and method of hanging a preformed exterior wall panel from spaced apart points on the main structure of a building.

The features of the invention which are believed to be novel are set forth with particularity and distinctly claimed in the concluding portion of this application. The invention, however, both as to its operation and organization, together with further objects and advantages thereof may best be appreciated by reference to the following detailed description taken in conjunction with the drawings, in which:

FIG. 1 is an end view of a plurality of beams in side by-side relation on a supporting wall to form a roof span;

FIG. 2 is a plan view ofa portion of the beams of FIG. 1 and a facia member adapted to conceal the ends of the beams;

FIG. 3 is a view in section of a facia member assembled to the beams of FIGS. 1 and 2;

FIG. 4 is a view in section of a wall panel assembled to horizontal upper and lower slabs;

FIG. 5 is a view in perspective of a spandrel member supported from two spaced apart vertical columns;

FIG. 6 is a front elevation of an element used in the construction of FIG. 5;

FIG. 7 is a sectional view of an alternate arrangement of a portion of the structure of FIG. 5; and

FIG. 8 is a view partly in section of another structural arrangement embodying the invention.

FIGS. 1-3 illustrate a vertical supporting wall 10 which supports a plurality of precast concrete beams 11 in sideby-side abutting relationship. The beams 11 which are generally utilized where there is an uninterrupted span between two supporting walls are illustrated as being of the common T-shape having depending webs 12 with abutting horizontal flanges 13. The upper surfaces of the beams 11 define a roof which may be suitably coated for weather proofing.

Due to ordinary manufacturing tolerances, shrinkage, etc. the beams 11 may not all be of the same length and their ends 14, accordingly, will not be aligned, as exemplified in FIG. 2. This possible discrepancy in dimension as well as any discrepancy in the vertical dimension is compensated for by the present invention.

The beam 11 has a threaded sleeve 15 cast into the web 12 of each beam 11. An angle 16, together with the head 17 of a large bolt or stud 18, is cast in the upper portion of beam 11. The sleeve 15 may have ex tensions or anchors 19 extending therefrom to lock sleeve 15 in the web while the angle 16 may have one or more extensions or anchors 20 for the same purpose. Preferably the head 17 is welded to angle 16. The angle 16, together with bolt 18, may be located at any point in the upper portion of each beam 11 either in line with the web or offset on one of the flanges.

A precast concrete facia beam 21 is adapted to be attached to and conceal the ends of beams 11. The facia beam is cast with a plurality of lower plates 22 embedded and locked therein as by means of extensions or anchors 23. The plates 22 are spaced along the length of beam 21 corresponding to the distance between the webs 12 of beams 11. Sleeve 15 is adapted to receive a headed bolt 24 which is adjusted to contact and bear against plate 22. At the upper corner of beam 21 facing the beams l 1 are embedded a plurality of spaced apart angles 25 having one leg 26 thereof adapted to overlie the bolts 18 embedded in beams 11. The overlying leg 26 is provided with an elongated slot 27 which receives therethrough bolt 18. Bolt 18 receives thereon a first nut 28, a washer 29 which resides beneath leg 26. Bolt 18 further receives thereon an upper washer 30 and a clamping nut 31. The angle leg 26 is supported and clamped in a horizontal plane dependent upon the position of nuts 28 and 31 and washers 29 and 30.

The angles 25 may be provided with one or more extensions or anchors 32 to lock the angles 25 in facia beam 21.

In assembly, after the beams 11 have been erected on the supporting walls 10, a horizontal chalk line L parallel to the desired line of the facia beam 21 may be snapped on the flanges of the beams 11. All of the bolts 24 are backed out until the heads thereof reside in a vertical plane parallel to line L and spaced the minimum distance D possible from the ends of beams 11. All of the nuts 28 and washers 29 are set so that the upper surface of the washers 29 reside in a common horizontal plane.

The facia beam 21 is then lifted in position so that the slots 27 receive therein the bolts 18. The inside surface 33 of the facia is moved inwardly until all of the plates carried by beam 21 are contacted by the bolts 24 and surface 33 resides in a vertical plane.

Using the same line L as previously established, a line of the facia which may be the interior surface thereof is set parallel to the line L. Then the washers 30 are in stalled and the nuts 31 tightened down thereon. This will provide support for the facia beam on the roof beams 11 and the contact between bolt 24 and plate 22 will prevent any turning moment of the facia. When it has now been established that the facia is properly adjusted horizontally and the proper distance from wall the head of bolt 24 is welded to plate 22 and the stud portion thereof is also welded to sleeve 15. The washers 29 and 31 and nuts 28 and may now be welded to each other through leg 26 and to the shank of bolt 18. When this is accomplished, any portion of bolt 18 extending above nut 30 may be burned off or otherwise removed. The space between the ends of the roof beams 11 and surface 33 of facia beam 21 may now be filled with any suitable grout with any necessary drainage channels defined therein.

This resulting construction provides a facia for the end of concrete beams which may be readily assembled and adjusted to the roof beams with a minimum of effort in leveling and aligning, and which provides a pleasing appearance along the ends of the otherwise unsightly roof beams.

If desired, and depending on available dimensions, the threaded sleeve 15 may be embedded in the facia beam with the bolt 24 bearing on the ends of the beams 11.

The invention is further adaptable to other precast structures. In FIG. 4 a precast wall panel is adapted to be mounted to help close a floor defined by an upper slab 41 which may be a roof and a lower slab 42 which may be a floor. Along the outside edge of the upper slab are cast a plurality of angles 43 together with the head 44 of a large bolt or stud 45. The head 44 is welded to the angle 43 to render it non-rotatable and an extension or anchor 46 from angle 43 may be provided to securely lock angle 43 into the cast slab 41. Bolt 45 carries a lower leveling nut 47 and washer 48 thereon, and also receives thereon an upper clamping nut 49 and washer 50.

An angle 51 is cast and embedded in panel at the upper edge thereof, and anchored with extensions 52. Angle 51 has an overlying leg 53 having an elongated slot 53a therein adapted to receive bolt therethrough. A threaded sleeve 54 is cast and embedded in slab 43. Sleeve 54 may have anchors 55 extending therefrom to secure it in slab 42. Sleeve 54 receives therein a threaded bolt 56 adapted to bear against a plate 57 carried by wall panel 40. Panel 40 is assembled to slabs 41 and 42 using the same technique previously described.

In this construction plates 58 and 59 are cast in panel 40 and slab 42 at intervals along the lengths thereof. A closure member in the form of an angle member 60 is disposed against slab 42 and panel 40 to close the gap defined therebetween. Angle member 60 is welded to plates 58 and 59 along the length thereof to further secure panel 40 to slab 42. This will provide additional reinforcement against any winch loading as well as closing the opening 62. If desired. the opening 62 may be filled with a grout or cement or other filler for insulation and weather proofing purposes. The space 63 may similarly be filled. The location of the sleeve 54 and bolt 56 may be in the lower portion of the panel 40.

From the foregoing it will be apparent that the structure disclosed may be used with facility to apply, align and level supported members fr 'm a supporting member or members. The leveling and clamping members are cast in the T beams and the slabs 41 and 42 and require no great tolerances inasmuch as any slight dimensional inaccuracies may be compensated for in the width or length of the slots 27. The leveling and clamping members as well as the lower spacing members may be easily formed and cast right into the structures at the time they are initially formed.

The invention may further be embodied in structures where the vertical member is hung from upright pillars or columns to support a spandrel as might be utilized in a parking garage. The structure of FIG. 5 comprises a plurality of upright load-bearing columns 71 spaced apart along a side of the building. A horizontal platform is provided which may comprise a plurality of prestressed concrete T beams 72 in side-by-side relation. The beams 72 are the conventional Tshaped providing a planar upper surface or platform. In the construction of the beams of the building threaded sleeves 73 are embedded in the ends of the beams to receive therein abutment bolts 74. Similar sleeves, not shown. are embedded in the facing surfaces of columns 71 to receive bolts 75 mounting brackets 76 to columns 71, as more clearly seen in FIG. 5. The bracket 76, FIG. 6, is in the form of a right angle with reinforcing fillets or gussets 77 and provides a horizontal portion 78 having a bolt or threaded stud 79 extending upwardly therethrough with its head welded to the underside of portion 78 as indicated at 80. The bracket 76 is fastened to the column 71 as by means of the threaded bolts 75 extending through horizontally elongated slots 81 then threadably received in the sleeves in column 71. Carried on bolt 79 is a lower nut 82 and directly thereover a large washer 83.

The columns 71 may be of the so-called treecolumn type which provide laterally extending supporting surfaces for beams 72. Alternately, the beams 72 may be supported in any suitable manner. The type of basic structure is not important to use of the invention.

The washers 83 and nuts 82 provide shaped apart surfaces in a substantially common horizontal plane between the facing surfaces of the column 71. The elongated slots 81 provide for adjustment of the bracket 76 to accommodate for any tolerance in the placement of the threaded sleeves in the column 71. The nut 82 is threaded adjustable along the length of bolt 79 so that the surfaces provided by the washers 83 may be adjusted vertically for proper leveling of a spandrel 84 as hereinafter described. It will be understood that a bracket 76 will be attached to the surface of the lefthand column of FIG. 5 opposite the bracket 76 on the righthand column.

Positioned at opposite ends of spandrel member 84 and bolted thereto are brackets 85. The brackets 85 have an upright portion adapted to be bolted to the inside surface of spandrel 84 by bolts 86 extending through elongated slots 87 therein into threaded sleeves cast into spandrel 84 in a manner heretofore described. The brackets 85 have an elongated slot (not shown) parallel to slots 87 through the horizontal por tion 88 thereof adapted to receive a bolt 79 therethrough so that the horizontal portion 88 will rest on the upper surface of washers 83. Spandrels 84 may then be secured to the column 71 through the use of an additional washer 90 and nut 91 received on each bolt 79. The spandrel is aligned in the vertical plane by placement of bolts 74 in a manner previously described. Troughs 72a may be defined in the ends of beams 72 to facilitate access to bolts 74.

In some types of construction where, as illustrated, the wall is a crash wall in a parking garage, the spandrels may be secured to the deck by additional means after leveling and alignment. As shown in FIG. 7, the spandrel 84 may have a longitudinally extending plate 92 embedded in its inner face and locked therein with integral anchors 93, and the beams 72 also have plates 94 with locking anchors 95 embedded therein. When the spandrel is assembled and leveled a longitudinally extending angle 96 is welded to plates 92. The brackets 84 and 76 may then be removed if desired.

It will be noted from FIG. 7 that the abutment bolts 100 are not disposed towards the lower edge of the spandrel 84 but are intermediate the ends thereof. The position of such bolts with respect to the upper spandrel brackets is not critical so long as they are disposed a sufficient distance therefrom to sufficiently react against any possible turning moment of the spandrel about its upper cantilever support. In FIG. 7, the abutment bolt is carried by spandrel 84. The abutment bolt may either be carried in the covering member or the basic structural member.

FIG. 8 exemplifies another finished construction embodying the invention, where it is desired to remove the brackets after leveling and aligning the spandrel. The spandrel 84 has reinforcing rods 10] cast therein along the length thereof. After assembly, a form 102 is placed to cover the opening between beams 72 and spandrel 84. Reinforcing rods 103 are positioned on the surfaces of beams 72 and a homogeneous finish concrete platform 104 is then poured. When the platform 104 has cured sufficiently, the leveling brackets may be removed. The spandrel is then tied to the deck along the length thereof.

The spandrel may be erected to the columns and platform as follows with reference to FIG. 8. A line L is established parallel to the inner face of the spandrel at a given distance D from it on the deck. Measure from the line marked on the deck the desired distance from the spandrel less a predetermined dimension M which for purposes of illustration will be considered to be one ft. Mark a plumb line P on the facing surface of the columns going through the point established in the second step. Establish a level line N on each side of the columns a predetermined distance, say one-half ft. lower than the desired top of the spandrel. Measure from the line on the deck a distance equal to the distance from the desired inside face of the spandrel and set the adjusting bolts this distance. Bolt the brackets 76 to the inserts cast into the column and align the edge of the brackets with the established plumb line using the elongated slots 84 for adjustment. Place the lower nut and washer on the upright bolt 79 and set the nut 82 so that the top of the washer is at the level established a predetermined distance of one-half ft. from the top of the spandrel. Measure the distance between the centers on the upright bolts 79 on the brackets 76 on the facing surface of the columns. Bolt the spandrel brackets 85 to the inserts cast in the spandrel and space the spandrel brackets 85 for use of the elongated slots 87 to adjust the center of the slots 87 equal to the distance between the centers on the bolts 79 on the column brackets. Erect the spandrel, landing the holes in the spandrel brackets over the upright bolts. Place the upper washers 90 and nuts 91 on the bolts 79 and tighten down. Previously the bolts 74 have been adjusted to provide abutments in a vertical plane a distance D from line L.

The spandrels have now been erected and the procedure is repeated for each spandrel and the columns which it spans along the length of each level of the building. The result is that all spandrels will be aligned horizontally and square with the building.

The invention may be embodied in various types of construction to hang a wall panel or a covering member from adjacent its upper edge to provide load support, and also to provide vertical alignment through adjustable abutments which also react against a turning moment at lower points.

It will thus be seen that the objects of the invention are efficiently attained. While preferred embodiments of the invention have been set forth for purposes of disclosure, modifications to the disclosed embodiment of the invention as well as other embodiments thereof may occur to those skilled in the art. Accordingly, it is intended to include in the scope of the appended claims all embodiments and modifications of the invention which do not depart from the spirit and scope of the invention.

What is claimed is:

1. In a building structure having structural members defining a building and a vertically disposed member providing an exterior covering or enclosure for said structure; first means extending generally horizontally from said vertical member adjacent the upper edge thereof and providing first surfaces, a plurality of second means attached and extending from portions of said structure each of said second means including threadably vertically adjustable members providing spaced apart supporting second surfaces, abutment means independent of said first and second mentioned means extending horizontally between a lower portion of said vertical member below said firstmentioned means and a portion of said structure defining points residing in a vertical plane. said second means supporting said vertically disposed member through said first means on said building structure on said second surfaces and said abutment means spacing said vertically disposed member with respect to said structure and reacting against a turning moment of said vertical mem ber about said support surfaces, said supporting surfaces being adjustable in the vertical to support said vertically disposed member in horizontal alignment with said structure.

2. The invention of claim 1 wherein said building includes spaced apart vertical columns and a horizontal platform therebetween; said second means being car ried on said columns above the platform, said abutment means extending between the edge of said platform and said vertical member.

3. The invention of claim 1 wherein said building includes vertically spaced apart horizontal platforms, said second means being carried by the upper of said platforms and said abutment means extending between the lower of said platforms and said vertical member.

4. The structure of claim 1 wherein said abutment providing means comprises bolts threadably received in one of said vertical member and said structure.

5. The structure of claim 3 wherein said second means comprises bolts carried by and extending upwardly from said upper platform and threadably carrying said surface providing means thereon, said first means comprising members carried by said vertical member and having slots therein adapted to receive said bolts therethrough and rest on said surfaces, and means for clamping said members on said surfaces.

6. The structure of claim 5 wherein said abutment means comprises bolts threadably received in the lower platform and adjustable therein to provide said abutments in said vertical plane.

7. A method of applying a vertically disposed enclosing member to the exterior of a structure comprising the steps of, providing spaced apart first surfaces essentially in a common horizontal plane on said structure, providing spaced apart members on said enclosing member adjacent the upper edge thereof having second surfaces residing in essentially the same plane, adjusting the height of said first surfaces to reside in an essentially common horizontal plane, supporting said enclosing member on said spaced apart first surfaces through said second surfaces, and spacing said enclosure member from said structure at points below said surfaces independently of said upper surfaces.

8. In a structure comprising a plurality of roof beams supported adjacent the ends thereof on bearing walls and a facia beam having upper and lower edges extending essentially perpendicular to the plurality of beams along the ends thereof; means extending vertically from said roof beams and providing surfaces in a horizontal plane, means extending substantially horizontally from the ends of said roof beams adjacent the lower portions thereof and providing abutments residing in a vertical plane, and means extending generally horizontally from said facia beam adjacent the upper edge thereof and engaging said vertically extending means and supported on said surfaces, said abutments engaging said facia beam in said vertical plane at points adjacent the lower edge of said facia beam.

9. The structure of claim 8 wherein said vertically extending means comprises bolts embedded in and extending upwardly from said roof beams and carrying said surface providing means thereon, said means extending horizontally comprising members embedded in and carried by said facia beam and having slots therein adapted to receive said bolts therethrough and rest on said surfaces, and means for clamping said members on said surfaces.

10. The structure of claim 8 wherein said abutment providing means comprises bolts threadably received in said roof beams and adjustable therein to provide said abutments in said vertical plane.

11. The structure of claim 9 wherein said bolts carry nuts thereon which provide said surfaces, and said means for clamping comprises second nuts received on said bolts over said plate members.

12. In a structure comprising at least one preformed horizontal member and a vertical member extending essentially parallel to said horizontal member along the ends thereof, said vertical member having upper and lower edges, a plurality of first means extending vertically from said structure with respect to said horizontal member and having thereon vertically threadably adjustable members defining an essentially horizontal support providing a plurality of supporting surfaces, second means extending horizontally from said horizontal member below said supporting surfaces and providing abutments residing in a vertical plane, and third means extending generally horizontally from said vertical member adjacent the upper edge thereof engaging said vertically extending means and supported on said surfaces, said abutments engaging said vertical member in said vertical plane below said first means and reacting against a turning moment of said vertical member about said surfaces. 

1. In a building structure having structural members defining a building and a vertically disposed member providing an exterior Covering or enclosure for said structure; first means extending generally horizontally from said vertical member adjacent the upper edge thereof and providing first surfaces, a plurality of second means attached and extending from portions of said structure each of said second means including threadably vertically adjustable members providing spaced apart supporting second surfaces, abutment means independent of said first and second mentioned means extending horizontally between a lower portion of said vertical member below said first-mentioned means and a portion of said structure defining points residing in a vertical plane, said second means supporting said vertically disposed member through said first means on said building structure on said second surfaces and said abutment means spacing said vertically disposed member with respect to said structure and reacting against a turning moment of said vertical member about said support surfaces, said supporting surfaces being adjustable in the vertical to support said vertically disposed member in horizontal alignment with said structure.
 2. The invention of claim 1 wherein said building includes spaced apart vertical columns and a horizontal platform therebetween; said second means being carried on said columns above the platform, said abutment means extending between the edge of said platform and said vertical member.
 3. The invention of claim 1 wherein said building includes vertically spaced apart horizontal platforms, said second means being carried by the upper of said platforms and said abutment means extending between the lower of said platforms and said vertical member.
 4. The structure of claim 1 wherein said abutment providing means comprises bolts threadably received in one of said vertical member and said structure.
 5. The structure of claim 3 wherein said second means comprises bolts carried by and extending upwardly from said upper platform and threadably carrying said surface providing means thereon, said first means comprising members carried by said vertical member and having slots therein adapted to receive said bolts therethrough and rest on said surfaces, and means for clamping said members on said surfaces.
 6. The structure of claim 5 wherein said abutment means comprises bolts threadably received in the lower platform and adjustable therein to provide said abutments in said vertical plane.
 7. A method of applying a vertically disposed enclosing member to the exterior of a structure comprising the steps of, providing spaced apart first surfaces essentially in a common horizontal plane on said structure, providing spaced apart members on said enclosing member adjacent the upper edge thereof having second surfaces residing in essentially the same plane, adjusting the height of said first surfaces to reside in an essentially common horizontal plane, supporting said enclosing member on said spaced apart first surfaces through said second surfaces, and spacing said enclosure member from said structure at points below said surfaces independently of said upper surfaces.
 8. In a structure comprising a plurality of roof beams supported adjacent the ends thereof on bearing walls and a facia beam having upper and lower edges extending essentially perpendicular to the plurality of beams along the ends thereof; means extending vertically from said roof beams and providing surfaces in a horizontal plane, means extending substantially horizontally from the ends of said roof beams adjacent the lower portions thereof and providing abutments residing in a vertical plane, and means extending generally horizontally from said facia beam adjacent the upper edge thereof and engaging said vertically extending means and supported on said surfaces, said abutments engaging said facia beam in said vertical plane at points adjacent the lower edge of said facia beam.
 9. The structure of claim 8 wherein said vertically extending means comprises bolts embedded in and extending upwardly from said roof beams and cArrying said surface providing means thereon, said means extending horizontally comprising members embedded in and carried by said facia beam and having slots therein adapted to receive said bolts therethrough and rest on said surfaces, and means for clamping said members on said surfaces.
 10. The structure of claim 8 wherein said abutment providing means comprises bolts threadably received in said roof beams and adjustable therein to provide said abutments in said vertical plane.
 11. The structure of claim 9 wherein said bolts carry nuts thereon which provide said surfaces, and said means for clamping comprises second nuts received on said bolts over said plate members.
 12. In a structure comprising at least one preformed horizontal member and a vertical member extending essentially parallel to said horizontal member along the ends thereof, said vertical member having upper and lower edges, a plurality of first means extending vertically from said structure with respect to said horizontal member and having thereon vertically threadably adjustable members defining an essentially horizontal support providing a plurality of supporting surfaces, second means extending horizontally from said horizontal member below said supporting surfaces and providing abutments residing in a vertical plane, and third means extending generally horizontally from said vertical member adjacent the upper edge thereof engaging said vertically extending means and supported on said surfaces, said abutments engaging said vertical member in said vertical plane below said first means and reacting against a turning moment of said vertical member about said surfaces. 